In the field of threaded cable hangers (cable-hanging metal bracket assemblies) for use in ships, and elsewhere, there are several factors that are of primary importance:
(a) that the electrical cables be hung effectively and strongly and permanently and easily, and in the desired locations and combinations;
(b) that the cost be low; and
(c) that it be very difficult or impossible to wreck the cable hangers by over-zealous application of muscle while threading the cable hangers onto threaded supporting studs.
Relative to the above factor (a), it should be possible to merely weld threaded studs to the wall (bulkhead) or ceiling (overhead), thread the cable hangers onto the studs until they are properly and permanently seated and are in the right orientations, and connect the cables to the hangers. Then, the hangers should strongly support the cables for as long a time as desired.
Relative to factor (b), the cable hangers should be capable of being made on a punch-press of one piece of sheet metal. Because of the high cost of punch-press dies, a single configuration of hanger should be readily capable of very different cable-hanging applications.
Relative to factor (c) it is emphasized that the sizes and shapes of some cable hangers are such that very strong persons can apply huge forces to the mated threads at the surfaces of threaded studs. It would be very desirable if even stripping of the original threads of the cable hanger or stud did not permit the cable hanger to move off the stud.
In accordance with a first embodiment of the invention, which may be called a heavy duty T-bar cable hanger, a strong bar is so constructed that there are three ways of strongly and properly associating it with a threaded stud. One is a reverse (protuberant) dimple that provides a seat for the end of the stud, and that permits the bar to make up to a full final turn so as to tightly relate the bar to the stud and also permit the bar to be in a desired orientation.
The second way is a stud stop that is disposed across the path of the stud, and that contains the above-indicated reverse dimple. The stud stop is so associated with the remainder of the bar that it may slowly bend from a configuration extending toward the stud to a configuration extending away from the stud, during all of which bending it absorbs energy and resists excessive torquing.
The third way is a pair of overlapping arms one of which is internally threaded to receive the stud and guide it toward the reverse dimple and stud stop. When there is a very large external force attempting to pull the bar off the stud, or when the torquing is so extreme that not only is the stud stop pushed over center from one side to the other but the torquing is continued thereafter, the arms start to unfold and accordingly create a binding action on the stud. This binding action is so effective that it holds the bar on the stud even if the original threads are stripped. However, it is a feature thatxe2x80x94despite the bindingxe2x80x94the bar may when desired be intentionally removed from the stud by reversing the direction of torquing.
The above elements, especially the overlapping arms and the stud stop, perform plural functions. Thus, for example, the threaded one of the arms is the normal threaded element that receives the stud, even if there is (as often occurs) only enough torquing to collapse the reverse dimple and not bend the stud stop or cause the arms to unfold. As another example, the stud stop is defined between two parallel slots; these receive bands that support the cables.
In accordance with a second embodiment of the invention, the above-indicated T-bar cable hanger is quickly and cheaply adapted for inverted (hangingxe2x80x94vertical stud) T applications. This is done by punching out the reverse dimple to create a hole sufficiently large that the stud may freely pass through it. A male/female elongate standoff spacer is provided for double (or triple, etc.) decking of the bars. Then, a bar is threaded upwardly onto a depending vertical stud, at the threaded hole in one of the above-indicted arms. The standoff spacer is then threaded onto the stud below the bar. This is repeated for as many decks of bars as is desired. The cables are banded to the bars.
In accordance with third and fourth embodiments, separate bands for the cables are not employed. Instead, integral metal arms support the cables. In the third embodiment, additional metal arms extend from a short channel having the above-indicated overlapping arms one of which is threaded. In the fourth embodiment, a return-bent sheet metal strip is internally threaded on one side to receive the stud. The other side of the return-bent strip is provided with the dimple (as is the flange of the third embodiment indicated above). The return-bent element extends in U-shaped configuration such that cables (one or several) nest therein and are supported thereby.